A content delivery network (CDN) is a distributed network of content delivery nodes. The content delivery nodes serve content to one or more clients requesting the content. The content delivery nodes are usually dispersed across many geographical locations. For example, one node may be located in New York and another may be located in San Francisco.
If a large multimedia file is downloaded, choosing a non-optimal location to serve the content may lead to a large penalty of content delivery. For example, a large amount of data will have to be transported across more network links. This may cause delay in serving the content to the user. For example, if a user is in San Francisco and the New York server is selected, additional latency may be experienced than if the server in San Francisco was selected and the content will have to be transported all the way from New York to San Francisco unnecessarily, thereby causing inefficient utilization of Service Provider networks.